Dustproof lamp holder



Dec. 12, 1967 E. A. GREASLEY 3,358,136

DUSTPROOF LAMP HOLDER Filed Oct. 8, 1965 United States Patent I 3,358,136 DUSTPROOF LAMP .HOLDER Eric Arthur Greasley, Stapleford, England, assiguor to Pressac Limited, Nottingham, England, a British company I Filed Oct. 8, 1965, Ser. No. 494,042

I Claims priority, application Great'Britain,

' Mar.'4, 1965, Ser. No. 9,2-18/65 4 Claims. (Cl. 2408.16)

This invention relates to a dustproof lampholder and more particularly to a miniature lampholder of the kind having a claw-type fixing for retaining the lampholder as a snap fit in an opening in an instrument panel, for example, in the dashboard of an automobile.

The main object of the present invention is to provide a miniature lampholder of the above described kind which is securely held in position and sealed so as to prevent the ingress of dust to the instrument in which the holder is incorporated. I

According to the present invention there is provided a lampholder comprising a body part formed at its lampreceiving end withan integral head constituted by a hollow tubular portion turned outwardly back upon itself and formed with an outwardly directed circumferential collar, the turned back portion and collar being slotted to form a number of closely disposed springy claw-like fingers.

When the lampholder is fitted in an opening in an instrument panel, printed circuit panel or the like, the head portion having the springy claw-like fingers is inserted through said opening from the inner face of the panel and the fingers initially contract radially to permit the head to be pushed through the opening and then, due to their inherent resiliency, tend to spring and bow outwardly again into tight frictional .contact with the edge of the opening so as to make sealing contact with the latter and so prevent ingress of dust through said opening to the interior of the instrument to which the lampholder or other article is fitted.

The holder is also held tightly in position against unintentional dislodgement due to the fingers being urged into contact with the edge of the opening by their inherent springiness.

In order to provide a still greater dust seal and to ensure a very efiicient fixing of say a lampholder in an opening in an instrument panel or the like, the holder may be fitted with a tubular flanged grommet capable of being slid axially over the body of the holder from the rear end thereof and sandwiched between the lampreceiving end of the latter and the springy fingers to urge the latter outwardly into tight sealing and gripping contact with the edge of an opening in a panel in which the holder is fitted. When the head of the body part is inserted into a panel aperture the tubular grommet is slid over the body part and sandwiched between the fingers and the outer face of the body part forcing the fingers radially outwardly against the edge of the panel aperture and securely retaining the holder to the panel, the flange of the grommet covering the collar-forming parts of the fingers on the inner face of the panel and sealing them against ingress of dust through any gaps left between the fingers and the panel aperture.

Preferably, the front or leading end of the grommet is tapered in thickness at its circumference to facilitate insertion of this end between the fingers and the outer face of the body part.

Conveniently, the slots in the collar pass right through the thickness of the extreme periphery of the collar and extend into the turned back portion at the lamp-receiving end of the holder.

It is to be appreciated that the holder may be used with or without the said grommet.

An important advantage resulting from the invention is that great tolerances on hole diameters and panel thicknesses can be accommodated due to the adaptability of the holder and in addition any force applied which would, with existing holders, result in the holder being unintentionally withdrawn, is resisted by the holder of this invention because the claw-like fingers tend to bow outwardly and so increase the holding power.

To enable the invention to be clearly understood a preferred embodiment thereof will now be described by way of example with reference to the accompanying drawings, in which:

FIGURE 1 is a side elevation of a lampholder according to the invention.

FIGURE 2 is a side elevation of the lampholder illustrated in FIGURE 1, mounted in an opening in a panel, with a supplementary retaining and dust-proofing grommet located in position before final assembly.

FIGURE 3 is a side elevation of the lampholder illustrated in FIGURES 1 and 2 partly in section.

FIGURE 4 is a perspective view of the grommet for retaining the lampholder in position and sealing the instrument to which it is fitted against the ingress of dust, and

FIGURES is a section showing the grommet fitted in position.

Referring to the said drawings, the lampholder comprises a body part 1 formed as an integral or composite moulding from a thermoplastics material and if required a tubular flanged grommet 2 may be provided also moulded from a thermoplastics material but one having more flexible proportions compared with that from which the body part is moulded.

, The body part 1 has a portion 3 WhiChhOllSCS the elec.

trical contacts (not shown) for the lamp and a hollow head 4 the wall of which is turned back upon itself as indicated at 5 and formed with a flange or collar 7 which surrounds the lamp-receiving end of the holder so as to leave an annular space between itself and the holder. This turned back portion 5 and collar 7 are slotted at 6 to form a number of claw-like fingers which are springy due to the nature of the material from which they are moulded. The slots 6 extend right through the thickness of the flange or collar 7 and into the turned back portion 5 where it surrounds the lamp receiving end 8 of the holder. If desired the slots 6 can extend into this end of the holder.

It will be appreciated that when the headed end of the holder is pushed through an opening in an instrument panel that the springy fingers will yield slightly radially inwardly and when the holder is in position will tend to spring outwardly radially so as to make a tight frictional contact with the edge of the opening so as to retain the holder firmly in position and also to prevent ingress of dust into the interior of the instrument to which the holder is fitted, the flanged portion 7 of the fingers surrounding the edge of the opening and covering to a great extent any crevices between said head of the holder and the opening.

As previously explained, the holder may if desired be fitted with a grommet to elfect a greater sealing and gripping action should this be found necessary.

The grommet 2 (FIGURE 4) has a tubular portion 9 one end of which is turned outwardly about its outer face to form a flange 10 which is curved in cross section, its other end being tapered in thickness at 11.

To mount the lamp holder in position, for example,

.on a dashboard panel 12 of an automobile, the head 4 of the body part 1 is inserted through an aperture in 3 the panel 12 from inside the latter causing the fingers to flex inwardly (see FIGURE 2) and abut at their ends against the rear of the panel 12. To secure the lamp holder in the panel against displacement by vibration and accidental withdrawal, the tubular flanged grommet 2 is located over the rea end of the body part 1 and slid over the latter and its tapered end 11 is inserted and sandwiched between the fingers and the body 3 forcing the springy fingers radially outwardly against the edge of the panel aperture. When the grommet 2 is completely pushed home its flange 10 covers the flanged ends 7 of the fingers and its periphery lies flush against the rear face of the panel thus forming a complete seal and preventing the ingress of dust to the instrument to which the holder is fitted through any crevices left between the head 4 and the edge of the panel aperture, as well as retaining the holder securely in position.

When it becomes necessary to remove the holder, the grommet 2 is pried from the rear of the panel 12 by its flange 10 and when it is withdrawn from between the fingers and the body 3, the head 4 of the body part 1 can be pushed through the aperture in the panel because with the removal of the grommet the fingers are free to flex radially inwardly.

I claim:

1. A lamp holder comprising a body part made of synthetic plastics material, an integral lamp-receiving head at one end of said body part, said head being constituted by a hollow tubular portion turned outwardly back upon itself, an outwardly directed circumferential collar formed integrally with said turned back portion, and slots formed in said turned back portion and the collar to form a number of closely disposed springy claw-like fingers directed axially of the holder.

2. A lamp holder comprising a body part made of synthetic plastics material, an integral lamp-receiving head at one end of said body part, said head being constituted by a hollow tubular portion turned outwardly back upon itself, an outwardly directed circumferential collar formed integrally with said turned back portion, and slots formed in said turned back portion and the collar to form a number of closely disposed springy claw-like finger directed axially of the holder, and a tubular flanged grommet slidable over the body part from the rear end thereof and capable of being sandwiched between the lampreceiving end of the holder and said springy fingers to urge the latter outwardly against the edge of an opening in which the holder is mounted with the flange of the groommet overlying the circumferential collar of the turned-back portion.

3. A lamp holder comprising in combination a body part made of a synthetic plastics material, an integral lamp-receiving head at one end of said body part, said head being constituted by a hollow tubular portion turned outwardly back upon itself so as to leave an annular space between the inner face of the turned back portion and the outer face of the body part it surrounds, an outwardly directed circumferential collar formed integrally with said turned back. portion, slots formed in said turned back portion and the collar to forma number of closely disposed springy claw-like fingers directed axially of the holder, and a tubular flanged grommet slidable over the body part from the rear end thereof and capable of being sandwiched in said annular space between the inner face of the turned back portion and the outer face of the body part it surrounds so as to urge said springy claw-like fingers outwardly against the edge of an opening in which the holder is mounted with the flange of the grommet overlying the circumferential collar of the turned back portion.

4. A lamp holder as claimed in claim 3, wherein the slots in the turned back portion extend into the adjacent portion of the body part surrounded by said turned back portion.

References Cited UNITED STATES PATENTS 1,031,976 7/1912 Weber 339-128 2,700,751 1/1955 Hallerberg 339-128 X 2,860,233 11/1958 Johnson 240-152 X 3,285,548 11/1966 Matto et al. .i 248-27 NORTON ANSHER, Primary Examiner. 

1. A LAMP HOLDER COMPRISING A BODY PART MADE OF SYNTHETIC PLASTICS MATERIAL, AN INTEGRAL LAMP-RECEIVING HEAD AT ONE END OF SAID BODY PART, SAID BEING CONSTITUTED BY A HOLLOW TUBULAR PORTION TURNED OUTWARDLY BACK UPON ITSELF, AN OUTWARDLY DIRECTED CIRCUMFERENTIAL COLLAR FORMED INTEGRALLY WITH SAID TURNED PORTION, AND SLOT FORMED IN SAID TURNED BACK PORTION AND THE COLLAR TO FORM A NUMBER OF CLOSELY DISPOSED SPRINGY CLAW-LIKE FINGERS DIRECTED AXIALLY OF THE HOLDER. 